A liquid friction clutch of said type is known from EP 1 731 787 B1.
Also, DE 197 49 342 A1 discloses a viscous clutch for driving motor vehicle air-conditioning compressors, in which, to control the filling level of fluid in a working chamber, the throughput of fluid through the pipe section adjoining an inlet section of a scoop pipe is controlled by means of a valve. Tests however yielded that such a valve causes problems in that it is extremely difficult to achieve acceptable performance results.
It is therefore an object of the present invention to provide a liquid friction clutch by means of which it is possible in a simple manner, without using a valve, to obtain a variable clutch fluid flow.